In a machine for manufacturing shells or thin-walled blanks from pulp material, the suction moulds may be permanently secured to a first rotor, with which they are moved in sequence through a container with a watery suspension of fibers of pulp material, during this movement by means of vacuum a shell of pulp material is aspired on to the liquid-permeable moulding surface. The pulp shell having been aspirated on to the moulding surface is now "rinsed", i.e. sprinkled with water, after which the suction mould is pressed together with an associated pressing-and-depositing mould suspended in a second rotor in the machine, and whilst applying pressurized air to the suction mould and vacuum to the associated pressing-and-depositing mould, the pulp-shell is transferred from the suction mould to the pressing-and-depositing mould, the latter by the continued turning on the second rotor being moved to a position above a pendularly suspended drying plate of an endless drying conveyor, on which the pulp shell is deposited by applying pressurized air to the pressing-and-depositing mould. Then, the moist pulp shells thus deposited are conveyed on the drying plates through a drier, so that they are dried, after which the dried pulp shells may be subjected to various post-processing steps as described in DK patent application No. 0763/92, before finally being subjected to a simple punching step, separating the individual articles being produced from the remainder of the pulp shell.
When used for manufacturing great numbers of articles, such a process of manufacture is simple and cheap to carry out, as especially the relatively high cost of manufacturing the mutually associated suction moulds and pressing-and-depositing moulds may in this manner be distributed over the very great number of articles manufactured.
When it comes to manufacturing a moderate number of articles, it is possible to let some of the mutually associated suction moulds and pressing-and-depositing moulds being mounted on and suspended in the two rotors respectively, be different from the remaining moulds. This will, however, entail the disadvantage of having to sort the dried pulp shells according to the type of articles manufactured on them, and then carry out the post-processing, including the punching-out, of the individual articles in separate post-processing lines. Even though this makes it possible to exploit the full capacity of the machine for manufacturing pulp shells, it is necessary in this case to distribute the cost of manufacturing the various mutually associated suction moulds and pressing-and-depositing moulds over a smaller number of articles, making the process of manufacture less profitable, and the same applies to the sorting of the various pulp shells and the post-processing of these in separate post-processing lines. Further, the requisite exchanging of the moulding tools cause the down time, of the machine, during which its capacity cannot be exploited, to be lengthened.
The disadvantages referred to above are, of course, even more noticeable, when the number of articles to be produced is even smaller, possibly making the cost of manufacturing the moulding tools prohibitive for such a production.